Health is the cornerstone of building a better life and a fundamental component of the stable and sustainable development of society. The United Nations highlighted this in the Sustainable Development Goals (SDGs) of 2015, particularly SDG 3 which focuses on promoting well-being for all ages and most of the remaining goals interrelate directly or indirectly with health. This impact was particularly noticeable during the COVID-19 pandemic. The COVID-19 pandemic underscored how health crises could amplify socio-economic and environmental disparities, hindering these goals. This chapter examines the pandemic's role in derailing progress on SDG 3, emphasizing the widening socio-economic inequalities impacting public health. It advocates for a reorientation of primary healthcare systems to effectively address social determinants of health such as socioeconomic status, education, and environment, as they significantly influence health outcomes and life quality. To promote population health, governments, academics, professionals and organisations must attend to the social determinants because good health not only enhances the quality of life and motivation of work but also helps to push the smooth implementation of more healthy policies and to allow the population to grasp health knowledge, a good way to maintain the commitment to achieving sustainable development goals in health.